Submission #347072

#	Time	Username	Problem	Language	Result	Execution time	Memory
347072		Pety	Finding Routers (IOI20_routers)	C++14	100 / 100	8 ms	876 KiB

routers

#include <bits/stdc++.h>
#include "routers.h"

using namespace std;

int answer[100002], lim[1002], lim2[1002];
int ask (int x) {
  if (answer[x] != -1)
    return answer[x];
  return answer[x] = use_detector(x);
}

vector<int> find_routers (int l, int n, int q) {
  vector<int>p;
  p.resize(n);
  memset(answer, -1, sizeof(answer));
  for (int i = 0; i < n; i++)
    lim[i] = l;
  for (int i = 1; i < n; i++) {
    int st = max(p[i - 1], lim2[i - 1]), dr = lim[i], poz = 0;
    while (st + 1 < dr) {
      int mij = (st + dr) / 2;
      int val = ask(mij);
      for (int j = 0; j <= val; j++) {
        lim[j] = min(lim[j], mij);
      }
      for (int j = val; j < n; j++) {
        lim2[j] = max(lim2[j], mij);
      }
      if (ask(mij) == i - 1) {
        st = mij;
        poz = mij;
      }
      else
        dr = mij;
    }
    p[i] = p[i - 1] + 2* (st - p[i - 1]);
  }
  return p;
}

/*int main () {
  return 0;
}*/

Compilation message (stderr)

routers.cpp: In function 'std::vector<int> find_routers(int, int, int)':
routers.cpp:20:55: warning: variable 'poz' set but not used [-Wunused-but-set-variable]
   20 |     int st = max(p[i - 1], lim2[i - 1]), dr = lim[i], poz = 0;
      |                                                       ^~~

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 40 / 40